The invention discloses a turnover machine. The turnover machine comprises a base, a machine frame, a lifting mechanism, a rotary mechanism and a clamping mechanism, wherein the lifting mechanism comprises a first lifting frame, a second lifting frame, a first backing ring and a second backing ring; the rotary mechanism is connected between the first backing ring and the second backing ring in a sliding manner and comprises a rotary part, a rotary support and a driving mechanism which is arranged in the machine frame and is used for driving the rotary part to rotate; rotary space for the rotation of the rotary part is formed between the rotary part and the first lifting frame and between the rotary part and the second lifting frame; the clamping mechanism comprises clamping oil cylinders arranged at the two ends of a circular arc opening of the rotary support, and clamping heads connected to the ends, close to the circular arc opening, of the clamping oil cylinders; and two clamping heads are oppositely arranged. The accurate overturning of straightening materials is realized through the transverse movement, lifting, rotation and clamping of the turnover machine. The turnover machine integrates machinery, electricity and liquid, can realize automatic control operation, is safe and reliable, has stable performances and high result intensity and is simple to operate.